Surgical device and method for bone surgery

ABSTRACT

A surgical device ( 1 ) for bone surgery comprising a body ( 2 ) able to be gripped by the user and a tip ( 3 ) mounted at the head of the body and set in vibration at a modulated ultrasonic frequency to operate on bone tissue, the surgical device ( 1 ) being particularly suitable for oral surgical procedures such as bone sampling, excision of cysts, third molar extraction, preparation of alveolar sites, creation of an opening into the maxillary sinus (Caldwell Luc), elevation of the maxillary sinus by the crestal route and orthopedic and neurosurgical procedures such as osteoplasty, ostectomy and osteotomy.

DESCRIPTION

[0001] The present invention refers to a surgical device and method forbone surgery. The device is particularly suitable, for example, fororthopedic surgical procedures such as osteotomy, ostectomy, osteoplastyetc. and for oral surgical procedures such as excision of cysts, thirdmolar extraction, preparation of implant sites, creation of an openinginto the maxillary sinus and elevation of the endosteum.

[0002] Bone surgery operations that involve cutting of the bony tissue(osteotomy) and/or modeling thereof (osteoplasty) have hitherto beenperformed with manual and/or rotary instruments. Manual instrumentsconsist of scalpels and/or chisels operated by hand or with a mallet.Rotary instruments consist of motor-driven milling cutters or disks.

[0003] These methods both have serious limitations if they have to beused in difficult situations such as restricted surgical access,anatomically difficult bone conditions and particularly when it isnecessary to operate in the vicinity of soft tissue.

[0004] The cutting characteristics of the techniques currently in useare unsatisfactory for the following reasons:

[0005] the cutting depth is poorly controlled;

[0006] the mechanical force is often excessive, therefore cuttingdirectionality is lost and/or accidental fractures are caused;

[0007] cutting is not selective and can therefore damage the soft tissue(for example the vascular nerve bundles).

[0008] The object of the invention is to eliminate these drawbacks byproviding a surgical device for bone surgery that makes it possible toperform surgical procedures with the utmost precision and therefore withless risk.

[0009] Another object of the present invention is to provide such asurgical device for bone surgery that is practical and versatile.

[0010] Another object of the present invention is to provide such adevice for bone surgery that is capable of cutting the mineralized bonetissue without causing cuts and lesions in the soft tissue, andparticularly in the neurovascular structures.

[0011] These objects are achieved according to the invention with thecharacteristics listed in appended independent claim 1.

[0012] Another object of the present invention is to provide a surgicalmethod for bone surgery that is most accurate, efficient and with lessrisk for the patient.

[0013] This object is achieved according to the invention with thecharacteristics listed in appended independent claim 14.

[0014] Preferred embodiments of the invention will be apparent from thedependent claims.

[0015] The surgical device for bone surgery according to the inventionprovides a handpiece comprising a tip capable of operating on bonetissue. For this purpose, according to requirements, various tips suchas chisels, compressors, osteotomes, periosteal or endosteal elevatorsetc. can be mounted on the handpiece.

[0016] The handpiece comprises a transducer, which can be piezoceramic,for example, and serves to generate sound waves that set the tip invibration. The tip is made to vibrate at a frequency within the sonicand ultrasonic range so that when it comes into contact with themineralized bone tissue an extremely fine and precise cut is made insaid tissue. Compression, compaction and displacement of said tissue isalso possible according to surgical requirements.

[0017] The surgical device according to the invention can be equippedwith a console which provides for the electrical and hydraulic supply tothe handpiece. The console has a keyboard that can be operated by theoperator to control the control electronics of the handpiece.

[0018] The control electronics allow the handpiece to be operated withsonic and/or ultrasonic vibrations, modulated or not at low frequency orwith low frequency bursts. In this manner the user can modulate theultrasound pulses to be transmitted to the tip of the handpieceaccording to the requirements of the surgical procedure.

[0019] The surgical device for bone surgery according to the inventionhas various advantages.

[0020] With the surgical device for bone surgery according to theinvention, the cutting action on the bone tissue is produced by variablemodulation ultrasonic vibrations that are activated only on the cuttingend of the tip that comes into contact with the mineralized tissue to becut. Consequently, the bone tissue surface affected by the action isextremely small. This allows the surgeon to draw the ideal type ofprocedure that he intends to carry out on the bone tissue with extremeprecision. Thus, for example, the actual cut made by the tip will differminimally from the ideal cut planned beforehand by the surgeon.

[0021] Another advantage of the surgical device according to theinvention is provided by the fact that, since the cut is extremely fine,the trauma suffered by the bone tissue due to the friction of thecutting instrument and the resulting heat loss will be minimal.

[0022] Furthermore, when the vibrating tip encounters soft tissue, suchas a neurovascular structure, it loses its cutting capacity. In fact thesoft tissue absorbs the vibrations of the tip without being resected andthe energy caused by the vibrations of the tip is dissipated in the formof a slight heat. This can be further reduced by the surgeon'spromptness in withdrawing the instrument as soon as he feels that itdoes not vibrate any more. The transmission of heat into soft tissue,such as neurovascular structures, therefore causes no irreparabledamage, as might be that caused by injury or cutting of such structures.

[0023] Consequently, if during an operation the surgeon touches aneurovascular structure with the tip, he has plenty of time to withdrawthe tip without the problem of causing irreparable damage. Thus use ofthe surgical device according to the invention makes it possible tosolve more severe clinical cases of bone surgery in which it isnecessary to operate in the vicinity of neurovascular structures.

[0024] For example, the device according to the invention can be used inoral surgery for the following types of operations.

[0025] bone sampling in anatomically difficult areas, whether for accessor because they are near the nerve endings or where there is extremelylittle bone tissue;

[0026] excision of cysts and/or of inflammatory or phlogistic tissue ofthe third branch of the trigeminal nerve;

[0027] extraction of impacted third molars in the vicinity of the dentalalveolus;

[0028] preparation of an implant site in the vicinity of nerve endings;

[0029] creation of an opening into the maxillary sinus (Caldwell-Luc)without damaging the sinusal membrane;

[0030] elevation of the maxillary sinus by the ethmoidal crest route.

[0031] The device according to the invention can also be used inorthopedic and neurological surgery, in operations such as:

[0032] osteoplasty;

[0033] ostectomy;

[0034] osteotomy in the vicinity of neurovascular structures as is thecase, for example, in vertebral surgery.

[0035] Further characteristics of the invention will be made clearer bythe detailed description that follows, referring to a purely exemplaryand therefore non limiting embodiment thereof, illustrated in theappended drawings, in which:

[0036]FIG. 1 is an axonometric view of a surgical device for bonesurgery according to the invention, complete with equipment foroperation thereof;

[0037]FIG. 2 is a block diagram illustrating operation of the surgicaldevice according to the invention;

[0038]FIG. 3 is an axial section of the surgical device in FIG. 1, witha connector element and a tip exploded;

[0039]FIG. 4 is a plan view showing five types of osteotomy tips;

[0040]FIGS. 5a, 5 b and 5 c show respectively three different types ofchisel insert and each figure shows a side view, a plan view and a viewfrom the other side;

[0041]FIG. 6 shows respectively a side view, a plan view and a view fromthe other side of a compressor tip;

[0042]FIGS. 7a and 7 b show two different types of universal tip andeach figure shows a plan view and a view from the right side,respectively;

[0043]FIG. 8 shows respectively a side view, a plan view and a view fromthe other side, of a periosteal elevator;

[0044]FIGS. 9a and 9 b show two different types of endosteal elevatorand each figure respectively shows a view from one side, a plan view anda view from the other side;

[0045]FIGS. 10a-10 f show the various stages of a surgical procedurecarried out with the surgical device according to the invention.

[0046] A surgical device for bone surgery according to the invention,indicated as a whole with reference numeral 1, is described with the aidof the figures. As shown in FIG. 1, the surgical device 1 is a handpiececomprising a body 2, substantially cylindrical in shape so that it canbe easily gripped by a surgeon. On the head of the body 2 is mounted atip 3 having a suitable shape for the various types of bone surgeryoperations for which the handpiece is intended, as will be describedbelow.

[0047] The body 2 of the handpiece is connected to an external connectorelement 4. The external connector 4 carries two electrical supply cables5 and 6 and a first hydraulic supply tube 7 which are wrapped inside asheath 8. The connector 4 also carries a second hydraulic supply tube 9.

[0048] The electrical supply cables 5 and 6 are connected to a console10 that takes its electrical supply from the supply mains or has anindependent supply system. The first hydraulic supply tube 7 isconnected to a hydraulic supply system, which can be provided in theconsole 10 or in a separate hydraulic system. The second hydraulicsupply tube 9 is connected to a peristaltic pump 11 provided on theconsole 10.

[0049] The peristaltic pump 11 comprises a rotor 12 with a controlledspeed of rotation so as to be able to vary the flow rate of the fluidsent, by means of the second tube 9, to the handpiece 1.

[0050] The console 10 provides a housing 13 in which the handpiece 1 ispositioned and a supporting rod 14 that supports a container 15, whichcan be a bottle or a bag, for example, which contains a sterile fluidthat must be used during the surgical procedure to bathe the surgicallytreated area. The tube 9 passes inside the peristaltic pump 11 and isinserted in the container 15 through an outlet 80. The sterile fluidfrom the container 15 is sent through the tube 9 to the peristaltic pump11 which in turn feeds the sterile fluid toward the handpiece 1. Thetube 9 and the outlet 80 of the container 15 can be supplied in steriledisposable packages.

[0051] On the console 10 a control keyboard 17 that can be operated bythe operator to control the microprocessor control unit 20 providedinside the console 10. With reference to FIG. 2, the electrical supplytaken from the electrical supply mains 21 is sent to a power supply 22provided inside the console 10. The power supply 22 provides electricalpower to the microprocessor unit 20, to a power stage 23 and to acontrol unit 24 of the peristaltic pump 11.

[0052] The power stage 23 is able to generate an adequate output currentand voltage signal to supply the handpiece 1. The control unit 24 of theperistaltic pump 11 gives out a control signal to operate the rotor 12of the peristaltic pump 11 so as to feed the sterile fluid from thecontainer 15 toward the handpiece 1.

[0053] The keyboard 17 generates control signals S1 toward the input ofthe microprocessor unit 20. The microprocessor unit 20, on the basis ofthe control signals S1 received, sends out output control signals S2 andS3 respectively toward the power stage 23 and the control unit 24 of theperistaltic pump 11.

[0054] The power stage 23, on the basis of the control signal S2received, sends the electrical supply to the handpiece 1. The controlunit 24 of the peristaltic pump 11, on the basis of the control signalS3 received, regulates the speed of the rotor 12 of the peristaltic pump11.

[0055] With reference to FIG. 3, the external connector element 4provides two electrical contacts 30 and 31 connected to respective wires5 and 6 of the electrical power supply. Furthermore the connectorelement 4 provides a hydraulic duct 32 connected to the hydraulic supplytube 7. The tube 9 can be clipped to the sheath 8 by means of a band 33.The external connector element 4 is destined to be inserted into acomplementary connecting element 40 provided in the rear part of thehandpiece 1.

[0056] The connector 40 provides two electrical contacts 41 and 42destined to come into contact with the contacts 30 and 31 of theconnector 4. The connector 40 also provides two ducts 43 and 44 for thehydraulic supply of the handpiece that couple respectively with the duct32 of the connector 4 and the tube 9. The duct 43 is stopped and servesto confine any fluid coming from the duct 32 of the connector. Thehandpiece is supplied by the fluid through the tube 9 which is insertedinto the connector of the duct 44.

[0057] The electrical contacts 41 and 42 are connected respectively toelectrical wires 45 and 46 which carry the electrical supply to atransducer 47. The transducer 47 is a piezoceramic resonator which mustbe supplied with alternating voltage and current. The transducer 47 ispreferably supplied with a sinusoidal voltage of about 160 V r.m.s. at afrequency ranging between 25 and 30 kHz.

[0058] To obtain this type of electrical supply, the console 10 has thepower supply 22 and the power stage 23 which act as an electricaltransformer, transforming the line voltage from supply mains into asinusoidal voltage of about 160 r.m.s at a frequency ranging between 25kHz and 30 kHz.

[0059] The transducer 47, when it is supplied electrically, acts as asound wave concentrator and sets a tang 48 provided in the head of thehandpiece 1 in vibration at an ultrasonic frequency. The tang 48 has athreaded attachment 49 for engagement in a threaded seat 50 of the tip3. Thus the ultrasonic vibrations are transmitted from the tang 48 tothe tip 3.

[0060] The microprocessor unit 20 of the console 10, through the controlsignal S2 controls the power stage 23 so as to allow different operatingmodes for supplying the transducer 47. In this manner the tip 3 can beset in vibration with ultrasound alone, with ultrasound modulated at lowfrequency (6-40 Hz), or with a series of low frequency bursts.

[0061] This method, which adopts modulation of the vibration of the tip3, allows the heat that develops on the soft tissue to be minimizedbecause of the dissipation of energy due to the vibration of the tip.

[0062] The method that provides for use of modulated ultrasound in lowfrequency bursts with a variable duty cycle, makes it possible to have ahammering effect of the tip, combined with the ultrasonic vibrationefficiency which produces a clean, precise cut in mineralized tissue.

[0063] The microprocessor unit 20 is able to perform various functions:

[0064] control of the power stage 23;

[0065] automatic tuning of the ultrasound that acts on the particulartip 3 used;

[0066] setting of the modulation, that is of the duration and frequencyof the bursts;

[0067] operation with bursts of increasing or decreasing amplitude.

[0068] For these purposes the microprocessor unit 20 has a series ofpre-set software programs for use with particular types of tips and inparticular clinical settings. These software programs can be updated orother software programs can be stored in the console 10 to make possibleapplications tested at a later date. Furthermore the user can setoperating parameters of his own choice through the control keyboard 17and store them in the console 10 for subsequent applications.

[0069] The hydraulic duct 44 of the connector 40 communicates with achamber 52 in turn communicating with a duct 53 provided inside the bodyof the handpiece. The duct 53 is connected to a tube 54 that carries thefluid toward a duct (not shown) inside the tang 48. From the duct insidethe tang 48 the fluid spreads into the seat 50 of the tip 3 and througha duct 55 made in the tip 3 it flows toward the outside. In this mannerthe fluid can irrigate the tissue on which the tip is working,minimizing the operating temperatures due to friction between the tipand the tissue.

[0070] In FIGS. 4-9 various types of tips that can be used in thehandpiece according to the invention are shown. In these figures thesame reference numerals indicate the same or equivalent parts. Each tipprovides a seat 50 able to engage with the threaded attachment 49provided in the handpiece 1. The seat 50 is connected to a stem 60having an axis substantially parallel to the axis of the handpiece 1.The stem 60 ends in an elbow part 61 connected to the head 62 of thehandpiece.

[0071]FIG. 4 shows five osteotome tips denoted by the abbreviationsOST1, OST2, OST3, OST4, OST5. These tips show a head 62 with a very wideblade 63 used for bone resection. The blade 63 must in fact cause afracture, breaking the continuity of the skeletal segment withoutcausing removal of bone tissue.

[0072]FIGS. 5a-5 c show three chisel-type tips denoted by the initialsT1, T2 and T3. The chisel tips have a thinner blade 64 than the blade 63of the osteotomes. In fact the chisel tip is intended for operations inwhich a very fine, precise cut in the bone tissue is required. For thispurpose the blade 64 of the chisel-type tip can have a diamond surfacefor greater cutting efficiency.

[0073]FIG. 6 shows a compressor-type tip is denoted by the initials CP1.This tip has a flattened part 65 in the head to compress the bonetissue.

[0074]FIGS. 7a and 7 b show two universal tips denoted by the initialsU1 and U2 which can be used for various types of operation.

[0075] In FIG. 8 SP1 denotes a periosteal elevator tip. This tip has aspoon-shaped head 66 to detach the bone from the membrane (periosteum)surrounding it.

[0076]FIGS. 9a and 9 b show two endosteal elevators denoted by theinitials SE1 and SE2. These tips have a spoon-shaped head 67 smaller insize than the spoon-shaped head 66 of the periosteal elevator. In factthe endosteal elevator must remove the connective tissue (endosteum)that lines the bone cavities.

[0077] A surgical technique using the surgical device 1 according to theinvention is described with the aid of FIGS. 10a-10 f. By way of examplea surgical procedure for implantation on an edentulous ridge isdescribed.

[0078] In FIG. 10a an edentulous ridge 100 is shown at the beginning ofthe surgical procedure. The thickness of the edentulous ridge 100,measured with a periodontal probe 101, ranges from 2.2 to 2.8 mm. Foredentulous ridges with such a small thickness an operation with theinstruments of the prior art such as cutters or chisels is impossible orextremely difficult.

[0079]FIG. 10b shows a side view of the edentulous ridge 100 of FIG. 1.This Figure was taken during the surgical operation and shows the typeof mucous flap of mixed thickness of the edentulous ridge 100. FIG. 10bshows a type T2 chisel-type tip driven by means of the ultrasoundhandpiece 1 according to the invention.

[0080]FIG. 10c shows the edentulous ridge 100 after the T2 chisel tiphas drawn a horizontal crestal incision 103 with two releasingincisions, one mesial and the other distal. In this figure it can beseen that the cut made by the T2 tip is extremely precise and fine.

[0081]FIG. 10d shows the edentulous ridge 100 after passage of a secondtype of chisel tip, V2, again mounted on the handpiece 1 according tothe invention and operated by ultrasound. The V2 tip has a widened pointto separate the vestibular cortical bone wall from the palatal one,according to the bone flap surgical technique.

[0082]FIG. 10e shows edentulous ridge 100 after two implant sites 104with a diameter of 2 mm have been created on the bottom of thehorizontal crestal incision 103. It has been possible to create implantsites 104 with such a small diameter, using an osteotome tip of the OST1type described with reference to FIG. 4. The OST1 tip has been mountedon the handpiece 1 and operated by ultrasound.

[0083]FIG. 10f shows the edentulous ridge 100 three months after theimplant. Two implants 105 are visible which have been placed in therespective implant sites 104, in the position for grafting bone materialbetween the cortical walls. The perfectly mineralized bone ridge isvisible and, after measurement with the probe 101, it has been possibleto detect an increase in the thickness of the bone ridge which has grownfrom about 2.5 to 5 mm.

[0084] The surgical device according to the invention can be used formaxillo-facial and otorhino-laryngol surgical procedures.

[0085] The surgical device according to the invention can be used forvertebral laminectomy treatments.

[0086] The surgical device according to the invention can be used forhand and foot bone surgery.

1. A surgical device (1) for bone surgery comprising a body (2) able tobe gripped by the user and a tip (3), mounted at the head of said body,having such a shape as to be able to operate on bone tissue,characterized in that inside said body (2) vibrating means (47) areprovided, operationally connected to said tip (3), to set it invibration at a frequency in the ultrasound range.
 2. A device accordingto claim 1 , characterized in that said vibrating means (47) comprise apiezoceramic transducer.
 3. A device according to claim 1 or 2 ,characterized in that inside said body (2) a hydraulic circuit (43, 44,52, 53, 54) is provided to feed a fluid toward an operating area of saidinsert (3).
 4. A device according to claim 3 , characterized in that itcomprises an external connector element (4) that can be coupled to acomplementary connecting element (40), integral with said body (2), tocarry the electrical and hydraulic supply toward said transducer (47)and toward said hydraulic circuit, respectively.
 5. A device accordingto claim 4 , characterized in that said external connector element (4)is operationally connected to a console (10) comprising electricalsupply means (22, 23) and hydraulic supply means (11) to electricallyand hydraulically supply said surgical device.
 6. A device according toclaim 5 , characterized in that said electrical supply means comprise apower supply (22) that takes power from the supply mains and a powerstage (23) that transforms the supply taken from said power supply (22)into an electrical signal able to supply said transducer (47) of thesurgical device.
 7. A device according to claim 5 or 6 , characterizedin that said hydraulic supply means comprise a peristaltic pump (11). 8.A device according to any one of claims 5 to 7 , characterized in thatsaid console (10) comprises control means (20) able to control theoperating functions of said surgical device (1), said control meanscomprising a microprocessor unit (20) that controls said power stage(23) and said peristaltic pump (11).
 9. A device according to claim 8 ,characterized in that said microprocessor unit (20) is configured totune the vibration frequency of the transducer (47) automatically andmodulate said vibration frequency, so that said tip (3) can vibrate withultrasound alone, with low-frequency modulated ultrasound or with aseries of low-frequency bursts.
 10. A device according to any one of thepreceding claims, characterized in that said tip (3) is an osteotome(OST1, OST2, OST3, OST4, OST5), a chisel (T1, T2, T3), a compressor tip(CP1), a universal tip (U1, U2), a periosteal elevator tip (SP1), or anendosteal elevator tip (SE1, SE2).
 11. A device according to claim 10 ,characterized in that said chisel insert (T1, T2, T3) has a diamondpoint for better cutting efficiency.
 12. A device according to any oneof the preceding claims, for use in bone surgery procedures.
 13. Adevice according to claim 12 , for use in oral surgical procedures, suchas bone sampling, excision of cysts, third molar extraction, preparationof alveolar sites, creation of an opening into the maxillary sinus(Caldwell-Luc), elevation of the maxillary sinus by the crestal routeand orthopedic and neurological surgical procedures such as osteoplasty,osteotomy and ostectomy.
 14. A surgical method for bone surgery,characterized in that it provides a surgical treatment on bone tissue bymeans of a tip set in vibration at a frequency in the ultrasound range.15. A surgical method according to claim 14 , characterized in that itis used in orthopedic and neurological surgery.
 16. A surgical methodaccording to claim 14 or 15 , characterized in that it is used inosteotomy treatments.
 17. A surgical method according to claim 16 ,characterized in that said osteotomy treatment provides bonerestriction, breaking the continuity of the skeletal segment, by meansof a osteotome tip set in vibration at a frequency in the ultrasoundrange.
 18. A surgical method according to claim 14 or 15 , characterizedin that it is used in osteoplasty treatments.
 19. A surgical methodaccording to claim 14 or 15 , characterized in that it is used inostectomy treatments.
 20. A surgical method according to claim 14 ,characterized in that it is used in oral, maxillo-facial andotorhino-laryngol surgical procedures.
 21. A surgical method accordingto claim 20 , characterized in that it is used in surgical proceduresfor implantation on an edentulous ridge.
 22. A surgical method accordingto claim 21 , characterized in that it comprises the following steps:horizontal crestal incision on edentulous ridge, by a chisel tipoperated by ultrasound, so that it performs an extremely precise andfine incision, widening of said incision, by means of a chisel tip, withwidened point, operated by ultrasound, to separate the vestibularcortical bone wall from the palatal one, creation of at last one implantsite on the bottom of the widened horizontal crestal incision, by meansof an osteotome tip operated by ultrasound, positioning of implants inthe implant sites respectively.
 23. A surgical method according to claim20 , characterized in that it is used for bone tissue incisions for bonesampling in hardly accessible anatomical areas.
 24. A surgical methodaccording to claim 20 , characterized in that it is used for excision ofcysts and/or inflammatory or phlogistic tissue.
 25. A surgical methodaccording to claim 20 , characterized in that it is used for extractionof impacted third molars in the vicinity of the dental alveolus.
 26. Asurgical method according to claim 20 , characterized in that it is usedfor creation of a bone opening into the maxillary sinus (Caldwell-Luc)without damaging the sinusal membrane, and elevation thereof.
 27. Asurgical method according to claim 20 , characterized in that it is usedfor elevation of the maxillary sinus by the ethmoidal crest route.
 28. Asurgical method according to claim 14 , characterized in that it is usedfor vertebral laminectomy treatments.
 29. A surgical method according toclaim 20 , characterized in that it is used for hand and foot bonesurgery.